Removal of volatile organic pollutants from drinking water

ABSTRACT

Volatile, toxic organic pollutants are removed from drinking water by partially filling a container with water and drawing a vacuum in the space above the water so that the pollutants exit the water into the space above the water for subsequent dispersement into the atmosphere.

This application is a continuation of application Ser. No. 08/353,184filed Dec. 9, 1994, now U.S. Pat. No. 5,458,184 which is a CIP ofapplication 08/088,671 filed Jul. 7, 1993, now U.S. Pat. No. 5,372,012which was a CIP of application Ser. No. 894,941 filed Jun. 8, 1992 (nowabandoned) which was a CIP of application Ser. No. 693,565 filed Apr.30, 1991 (now U.S. Pat. No. 5,152,150) which was a continuation ofapplication Ser. No. 581,676 filed Sep. 13, 1990 (now abandoned) whichwas a continuation of Ser. No. 395,568 filed Aug. 18, 1989 (nowabandoned).

This invention relates to health care and especially to prevention ofthe ingestion of toxic organic carcinogens. More particularly, theinvention relates to method for the removal of volatile toxic organiccarcinogens from drinking water. The invention contemplates the use ofstandard conventional equipment for carrying out the methods wherebyremoval can be effected simply and inexpensively at home with water fromthe tap or with water from commercially purchased bottled water.

FIG. 1 is an elevational view partially in section illustrating anespecially designed cap;

FIGS. 2, 3, and 4 are flow type diagrams illustrating equipment forpracticing the invention; and

FIG. 5 through 10 are views depicting the steps of an alternativemethod.

The potable water in the United States has been increasing in organicpollutants since the early fifties. The Environmental Protection Agencywas formed in 1972 and they have found several hundred toxic organics inour drinking water, which are called TTOs or total toxic organics. Manycompanies have tried to make purifiers for the home owners to removevarious pollutants.

Ion exchange units were introduced on the market, but only removedmetals. The systems were beneficial with respect to removal of sodiumfor heart patients but at the same time removed calcium which isessential to good health. Another alarming attribute was that if ionexchange resin was swallowed, it could cause liver cancer and the resindid nothing for the removal of the TTOs, which are considered the mostimportant aspect of the problem. Charcoal will absorb the toxicorganics, but the removal capacity is so limited that the unit must bekept off the main stream of the water and used only for drinking water.This criteria is also the downfall of such a system. I have found that acharcoal unit guaranteed for five years gave off more TTOs than itremoved after six months of operation.

For illustration, the incoming stream contained 2 parts per billion(ppb) of methylene chloride, 1 ppb of trichlorethylene and 3 ppb ofchloroform. After going through the charcoal and very fine filter, theanswer was surprising.

    ______________________________________    Methylene chloride  6.3 parts per billion    Trichloroethylene (TCE)                        2.7 parts per billion    Chloroform          4.5 parts per billion    ______________________________________

A good quality filter was used to stop any possible fragments ofcharcoal getting through. The instrument to measure these toxic organicsis a GC/MS, which stands for gas chromatograph with mass spectroscopydetection. Various other detectors can be used in place of the massspectroscopy. The normal sensitivity is 0.5 parts per billion for thechlorinated compounds.

The above tests were tried under varying conditions and it seemed thecharcoal loaded up very quickly. A scientist in Washington wrote anarticle on this phenomenon, which he called the wave effect. Even if thecarbon was not saturated, the idle water surrounding the absorbing bedwould become saturated with the various pollutants. When flushed thewater that was supposed to be safe, was now more polluted than theoriginal. Flushing for one minute or maybe two minutes might clear thecharcoal bed, but who wants to play Russian roulette with cancer.

People want a positive answer when it comes to removal of cancer causingagents or carcinogens from their drinking water. Taking a quart or twofrom an ordinary tap and boiling the water will remove the volatilecompounds, such as methylene chloride TCE and chloroform. Unfortunately,the water tastes bad, the process uses energy and the process is awkwardand time consuming.

I have found a simpler way to remove the pollutants, Add 11/2 quarts oftap water to a glass jar so that it is 3/4 full and leave it outovernight on the counter so that the water assumes the room temperature.Tap the bottle and screw the cap on tightly and place in therefrigerator for at least eight hours. The drop in temperature willcause a vacuum in the glass bottle and pull the carcinogens out of thewater. Heating the glass bottle slightly (150° F.) will create a bettervacuum. The foregoing may be accomplished by any conventional method.

    ______________________________________    Illustration 1    ______________________________________    Boston tap water                   4.5 ppb     TCE    After vacuum   not detected                               (less than .5 ppb)    Philadelphia tap water                   30 ppb      chloroform                   6 ppb       methylene chloride                   1.4 ppb     TCE    After vacuum   not detected                               (less than .5 ppb)    Orlando, FL tap water                   3.1 ppb     TCE                   1.8 ppb     chloroform    After vacuum   not detected                               (less than .5 ppb)    ______________________________________

Illustration 2

I gave the instructions to a local water company. After several daysthey called and said the process did not work. Further investigationrevealed that they pulled a vacuum with a pump for only ten minutes andthe results were

    ______________________________________    Water company     2.1 ppb   chloroform    After vacuum (10 Min.)                      2.0 ppb    ______________________________________

After trying many combinations, it appeared that five hours were neededto bring the chloroform down to the detection limit.

    ______________________________________    Water company sample                      2.1 ppb   chloroform    After vacuum       .5 ppb   chloroform    ______________________________________

It appears that it is important to lower temperature and pressuretogether and slowly.

    ______________________________________    Water company sample                      35° F.                                2.1 chloroform    After vacuum 8 hours                      35° F.                                No detection    ______________________________________

Some research was devoted to placing a vacuum pump in a refrigerator andthis proved successful but very expensive. A bottle and vacuum gaugewould be less than $25.00 whereas a vacuum pump would be over $500.00.On a mass production basis the costs would be greatly reduced and theTTOs vented outside the refrigerator.

In recent months I have asked a number of people to try a set of bottleswith vacuum gauge and without it. They definitely wanted the vacuumgauge. It was found the sealing ability of the screw caps was soon lostand the possibility of preventing cancer by the removal of thecarcinogens was too important to fool with. A positive measure of thevacuum in the bottle was essential.

The problem of losing the vacuum after 20-30 turns was solved by using aspecially designed cap. While I am not ruling out the possibility ofusing metal caps, it appeared likely a plastic cap would hold up for1000 openings and closings. There was less chance of an off-taste withplastic caps. Many testers remarked that the water tasted better thanbottled water.

This prompted me to check several different bottled waters.

    ______________________________________    BOTTLED WATER NON CARBONATED    ______________________________________    Sample A    chloroform        17.4 ppb.                carbon tetrachloride                                  2.1 ppb.    Sample B    methylene chloride                                  3.9 ppb.                toluene            .6 ppb.    Sample C    methylene chloride                                  4.6 ppb.                bromodichloromethane                                  2.1 ppb.                1,1,1-trichloromethane                                  1.8 ppb.                chloroform        1.7 ppb.    ______________________________________

Pulling a vacuum by cooling in a refrigerator overnight proved to lowerall carcinogens below the detection point.

With respect to the above mentioned specially designed cap, a typicalcap is illustrated in FIG. 1. The cap has a body 1 lower internalthreads 2, a cavity 3 designed to accept the tops of the neck of a waterbottle or container, a neck 4 having internal threads 5 and opening 6.The neck 4 and threads 5 constitute a fitting 7 to which can be attachedthe stem of vacuum gauge on a vacuum pump.

The annular lip 8 extends down into the bottle or container and when thecap or cover is tightened down it measurably enhances the seal.

The container referred to above can be formed from glass or plasticprovided the material has the rigidity to withstand vacuum. If cap is tobe molded from plastic I prefer polypropylene.

It will be appreciated that a vacuum gauge or a vacuum pump can easilysecured to the fitting 7. Naturally, the fitting can be plugged up inthe event a vacuum gauge is not desired and/or the vacuum is not to becreated by a pump.

I have referred to the components for removing the pollutants asconventional and standard. This is true of the GC/MS equipment eventhough this equipment is not ordinarily available in a dwelling. Withrespect to GC/MS equipment it is contemplated that the container forwater and it's cap or cover be precalibrated.

If the container and cap are to be used with a vacuum pump, informationon the vacuum level and the time under vacuum for desired removal areprovided. Normally this will be 6-7 inches of mercury held for about 8hours.

If the container (with cap or cover) is to be set up in a refrigeratorfor the vacuum creation, information on the desired refrigeratortemperature and the time to be spent in the refrigerator for desiredremoval are provided.

With respect to time and temperature the following chart will provide aguide.

    ______________________________________    Inches of Mercury                    Time(hours)                               Temp(°F.)    ______________________________________    4               48         35    5               24         35    6               10         35    7                8         35    ______________________________________

With respect to the testing time period with GC/MS equipment thefollowing is to be noted.

When a container is taken from the refrigerator and a sample removed andtested in the GC/MS equipment it will be necessary to return thecontainer to the refrigerator if the reading is more than 1/2 part perbillion. Before returning the container to the refrigerator, watershould assume room temperature. This may be done by leaving thecontainer out of the refrigerator overnight.

With the methods herein note that the volatile pollutants in the spaceabove the water are dispersed into the atmosphere when the containercover is removed. This is not detrimental in as much as the density inthe atmosphere is negligible as compared to the density in the water.

As will be understood, the above described arrangements for drawing avacuum by a pump each contemplate (like the version of drawing thevacuum by refrigeration) that water be obtained from the container byremoving the cap.

In the event it is desired to obtain water via a spigot on the bottom ofthe container, a valve should be secured to the cap (say fitting 7)which can be activated to open the space above the water in thecontainer to the atmosphere and thereby break the vacuum. After thewater is drawn off, the valve can be activated to seal the space andpermit the vacuum to again be created.

The valve and the spigot can be operated in coordination with oneanother, either manually or automatically.

In connection with the spigot/valve arrangement. I want to point outthat there are vacuum pumps now available which can draw vacuums up to30 in. of mercury and which are of a size and cost making same feasibleto be used in my method. These pumps provide an additional advantage inthat the same can be employed to purge the carcinogens in the spaceabove the water. For such purposes, a needle valve is provided on thebottom of the container (near the spigot) which when opened will allowair to be pushed up thru the water and bubble out into the space. In themeantime the vacuum pump is activated to begin to evacuate the space.The foregoing is done over a short period of time and the needle valveclosed and the vacuum pump stopped. The valve in the cap and the spigotboth can be opened and water drawn off.

It will be understood that the just described spigot and valvearrangement can be employed in a refrigerator.

Further, it will be self-evident that automatic means can be providedfor filing the container and light means can be employed with a vacuumgauge to indicate or alert that the desired vacuum has been reached.

In FIGS. 2, 3, and 4 I have provided sketches diagrammaticallyillustrating equipment for practicing the inventions as defined inclaims 1-6.

In FIG. 1, the container 10 has a screw-on cover 11 with a fitting 12.The standard vacuum pump 13 has a fitting 14. The fittings 12 and 14 areconnected by line 15.

The GC/MS equipment is indicated at 16 and has a port 17 into whichwater from the container 10 can be poured.

In FIG. 3, the container 20 has a screw on cover 21. A valve 22 isconnected to the top interior of the container and has a fitting 23. Thevalve 22 is adapted to connect the interior of the container 20 eitherto the atmosphere or to fitting 23. The vacuum pump has a fitting 25.The fitting 23 and the fitting 25 can be connected by a line indicatedby the dotted line 26.

Near the top, the container has a spigot 30 thru which water in thecontainer can be emptied. Near the bottom the container has acontrollable needle valve 31 (manually operated) in conjunction with thevacuum pump 24.

FIG. 4 illustrates a refrigerator 32, having doors 33 hinged at 34 anddoor opening handles 35.

The refrigerator is large enough to receive the container mentioned inconnection with FIGS. 2 and 3.

I will now explain a simplified method for attaining the objectives ofthe invention.

Preferably, this is done by using an extra thick plastic bottle, fillingwith hot steaming water, tightly closing the bottle, allowing it to cooldown in a room temperature environment for approximately two hours, andthen placing in a refrigerator, such as a household refrigerator, andallow to cool for at least five hours. Usually, the bottle remains inthe refrigerator overnight.

Hot steaming water has a temperature of substantially between 160°-200°F. At that temperature range, steam vapor rises from the surface.

As indicated heretofore, a household refrigerator will have atemperature range between 32° F. and 40° F.

The bottle or container must be constructed, when closed, to sustain aninternal vacuum and to withstand the temperature range of hot steamingwater. I have used high density polyethylene as the plastic materialwith a wall thickness in the side, bottom, and pouring throat ofapproximately 1/8 inch. This provides the necessary strength to preventcollapse under internal vacuum. A thicker wall may be used if desired.

The bottle or container is conveniently in the shape of a one gallonplastic milk bottle with the wall thickness as above indicated.

Normally, glass cannot be used as it would eventually fracture underthermal shock and if dropped on a hard surface when under vacuum itwould blow up like a bomb.

I want to point out that the step of allowing the partially filledbottle to cool down in a room temperature environment can be eliminatedand the bottle placed directly in the refrigerator.

The advantage of the two step method is that there is a saving in energywhich is very important to the national energy saving programs. Also,the two step method is preferred because I believe more of thecarcinogens are removed that in the one step method.

An alternative method is shown in FIGS. 5-10. The equipment needed forthis alternative method includes: a plastic bottle of the kind referredto above but which additionally has an open gauge holder; a length ofplastic tubing; an air pump; and a vacuum gauge. Below, with thereference to FIGS. 5-10 I will outline the alternative method.

1. Fill bottle to top indentation with hot tap water (135-145 degrees).

2. Insert air tube and aerate making sure the air tube goes to thebottom of the bottle. Remove after 10 minutes.

3. Put top on tight--Shake vigorously with finger over the open gaugeholder. Stop to release air once or twice.

4. Shake again. Quickly place vacuum gauge over the open gauge holder.

5. Cool on counter for about 2 hours. Vacuum gauge should read about 2-3inches.

6. Place in refrigerator for 5-8 hours. Vacuum gauge reading should bein the dark blue section (5-9 inches) after 5 hours in the refrigeratorand be ready to drink.

Another alternative method particularly applicable as respectsrefrigerators is discussed below.

The United States Environmental Protection Agency prefers that the toxicorganics in drinking water be called volatile organic compounds orV.O.C. Previously they were called T.T.O.s or total toxic organics.Limits of detection were in the order or one half to one part perbillion. Our method of removal of the carcinogens (VOC) was always belowthese figures and after several years of research analytical answers inthe order of 20-70 parts per trillion were obtainable.

We have found an interesting comparison between two plastic bottles at150° F. which obtained a vacuum of ten inches. The first one was airswept for ten minutes and the other without air. I thought air bubblingmight add carcinogens from the air but it was just the opposite. The airbubbled bottle showed less trichloroethylene (TCE) and less chloroformthan the non-aerated bottle. While many other volatiles are present, TCEis the most common (1-5 ppb) and certainly one of the most potentcarcinogens known to the human body. Chloroform is less toxic but isoften present in the range of 20 to 180 ppb which places it at thehighest level of any of the contaminants. Blank runs often show higherlevels than the expected levels of our specific contaminate. Forexample, one laboratory would show 670 ppt chlorobenzene and a splitsample with a second laboratory would show less than 50 ppt. Previouslyboth results would have shown beyond the limits of detection. On theother hand, split samples of TCE showed the following:

    ______________________________________                      First lab                             Second lab    ______________________________________    TCE, no bubbling    170 ppt  135 ppt    TCE, air bubbling, ten minutes                         95 ppt   92 ppt    ______________________________________

These experiments suggested that perhaps the air space was too limitedand the air space was increased from 25 percent to 40 percent with thefollowing results. The temperature was maintained at 150° F. at thestart of the vacuum and the vacuums ran 10±1/2" of mercury column.

    ______________________________________                  First lab                         Second lab    ______________________________________    TCE, no bubbling                    47 ppt   52 ppt    TCE, air bubbling                    58 ppt   40 ppt    ______________________________________

If the blanks are subtracted from these figures in the first lab, theanswers would be zero, but this is highly unlikely. In the second labthe answers averaged 20 parts per trillion. Experiments with chloroformshowed higher levels as the starting concentration in the tap water wasabout 50 ppb and TCE was 2 ppb. Considerable decrease in the chloroformlevel was noticed by increasing the air space above the water from 25%to 40%. Still another experiment was run with 50% air space and 50% tapwater and this seemed to be near perfection.

The temperature was increased to 160° F. and while results were lower,the plastic jugs began to deform. Stainless steel containers are bingconsidered and one was tried for automatic use built right into arefrigerator, but stainless would cost 20 times as much as plasticbottles. Under no circumstances should a glass bottle be used since itwill implode if dropped or under continual heating and cooling.

Some of the above work was done to develop a continuous unit built rightinto a refrigerator or a separate purification water unit such as for arestaurant. A second purpose of this work was to eliminate the airbubbling and still obtain high quality water. Usually water out of thehot water tap is between 125°-135° F. Heating the water to 165° F. in amicrowave oven has the further advantage of killing any microbes thatmight be in the drinking water. A number of people have died in recentyears in major cities in the United States because public water worksfailed to kill all microbes.

By inserting a stainless unit in a refrigerator the bottle can besmaller with a required air space of only 5 percent. The water is heatedto 150°-160° F. and a vacuum pump is turned on after the water chillsdown to 120° F. The pump continues until the temperature reaches 110° F.and an air sweep removes the carcinogens for 30 seconds. The air sweepvalve is turned off and a 10 inch vacuum is maintained until the waterreaches 35°-50° F. The purified water is pumped to a 1-5 galloncontainer, which is at normal atmospheric pressure. It takes about twohours to make a batch and the reactor can be 1, 2, 3, or 4 quarts andthe unit will automatically shut down when the storage tank (1-5gallons) is full. There is no limit on the size of the unit to deliversafe drinking water. Time in the reactor is only two hours compared witheight hours in the bottle method because the air sweep is drawn undervacuum. The readings in parts per trillion are slightly lower than thebottle method and has the further advantage of being fully automatic. Itis difficult to ascertain the levels of various carcinogens below 50parts per trillion and public water works and wells alike are showingincreasing concentrations of cancer causing agents. In 1994 breastcancer became the leading site specific cause of death in women in theUnited States--about 200,000. Some scientists argue that DDT caused thesurge in breast cancer, but DDT has not been used since 1966. Latency istypically 20 years, which would indicate in 1986 the incidence of thistype of cancer would wane. However, it has done just the opposite andtripled approximately in the last eight years. If we strip away the twoDs from DDT we have TCA, a common carcinogen in our drinking water.

In 1993 the Zerpol Corporation removed a TCA vapor degreaser. TCA is1,1,1 trichloroethane and this was the only material ever used in thevapor degreaser, but analysis of the sludge in the pit under the vapordegreaser showed two thirds TCE and one third TCA. Drinking water willcommonly show 2-4 parts TCE and about one part per billion of TCA.

If pure TCE comes in contact with water or moisture, it forms TCA in amatter of hours at elevated temperatures. Inhibitors, such as variousamines, slow down the reaction but the end results are the same and viceversa when starting with TCA.

The Environmental Protection Agency has tried to outlaw TCE and TCA butwithout success and yet DDT was outlawed. Chlorodane was outlawed. EPAcould start by lowering the TTOs from 2.13 mg per liter (2130 ppb) to 10ppb for industrial discharge of wastewater.

Before closing I want to point some additional facts.

It appears that there is a balance of the volatile organic compounds inthe air space above the water which is effected by the ratio of watervolume to air volume, temperature, amount of VOC in the water at thestart, and inches of vacuum. If the vacuum is three inches at roomtemperature, it will remove most of the VOC in eight hours providing thecarcinogens are between 10-50 parts per billion, whereas 10 inch vacuumwill remove an equal amount in three hours elevating the temperaturewill reduce the time for removing the VOC from the water but only withincertain limits in a confined space. Usually about 160° F. is the maximumefficiency. However, higher temperatures are effective if an air sweepis used under vacuum to rapidly remove the volatile organics from thecontainer.

These concepts helped to develop a compact stainless steel unit forcontinuous service built into a home refrigerator. While stainless steelis the preferred construction other materials can be used and aspolyethylene, aluminum, ceramics, or similar materials. The incomingwater can be hot or cold, but hot is preferred to insure killing thebacteria such as from a well. The first container, preferably stainless,can be one quart to one gallon and the air space requirement is only5-10 percent of the container. The reason for the small space is, whileunder vacuum, a timer open a valve at the bottom of the closed vesseland sucks in air due to the 10 inch vacuum. The aerator is designed toproduce very small bubbles which remove the carcinogens much faster.Only two hours are required. The temperature may be adjusted at thestart to 200° F. to kill microbes, but the temperature should be down to35° to 50° F. at the finish. Ideally the aerator should run for 10minutes when the temperature is between 140° F.-150° F. and a vacuum of10-15 inches.

The second container should be between two and five gallons and isusually made of polyethylene. Buyer of the refrigerator should have achoice of size. For example, a family of five would use four gallonreservoir would be adequate with a two quart reactor feeding the storagetank every two hours. The unit will automatically shut down when full.All temperature are adjustable as well as vacuum and times.

There is no limit on the size of the water purifier units to deliversafe drinking water whether it is in a refrigerator, single unit forrestaurants, and large manufacturing plant.

I claim:
 1. The method of removing volatile, toxic substances fromdrinking water comprising the steps of:providing a container which canbe opened and closed and which is constructed, when closed, to containwater and to sustain an internal vacuum and also constructed with apassageway configured to receive and support the rubber stopper of avacuum gauge; opening said container and partially filling the containerwith drinking water having a temperature range of approximately 135-145degrees F.; aerating said water for not over 10 minutes; closing offsaid container and placing said rubber stopper in said passageway;storing said container and the vacuum gauge thereon substantially atroom temperature until the vacuum gauge shows approximately 2-3 inchesof mercury; and placing the container with vacuum gauge showingapproximately 2-3 inches of mercury in a refrigerator to permit thevacuum gauge to show approximately 4-9 inches of mercury.
 2. The methodof removing volatile, toxic substances from drinking water comprisingthe steps of:providing (a) a vacuum gauge with a rubber stopper and (b)a plastic container having an opening covered with a removable cap bywhich the container can be opened and closed and a passageway adapted toreceive the rubber stopper of the vacuum gauge; removing said cap andpartially filling said container with hot drinking water; replacing saidcap and while closing off said passageway shaking said container andstopping the shaking at least once and release air; after said shaking,immediately placing the vacuum gauge stopper in said vacuum gaugepassageway; storing said container substantially at room temperaturewith the vacuum gauge thereon until the vacuum gauge shows approximately2-3 inches of mercury; and placing said container and vacuum gaugeshowing approximately 2-3 inches of mercury in a refrigerator to permitthe vacuum gauge to show approximately 4-9 inches of mercury.
 3. Themethod of claim 2 wherein said hot drinking water has a temperaturerange of approximately 135-145 degrees F.
 4. The method of removingvolatile, toxic substances from drinking water comprising the stepsof:providing (a) a vacuum gauge with a rubber stopper; (b) a length ofplastic tubing, (c) an air pump; and (d) a plastic container having anopening covered with a removable cap by which the container can beopened and closed and a passageway configured to receive and hold therubber stopper of a vacuum gauge; removing said cap and partiallyfilling said container with drinking water having a temperature rangebetween approximately 135-145 degrees F.; placing said tubing throughsaid opening with one end adjacent the bottom of the container andconnecting the other end to said air pump and aerating said water for aperiod of not more than approximately 10 minutes; removing said tubingand replacing said cap and while closing off said passageway shakecontainer and stopping at least once to release air; after said shaking,immediately placing said vacuum gauge stopper in said vacuum gaugepassageway; storing said container with the vacuum gauge thereonsubstantially at room temperature until the vacuum gauge showsapproximately 2-3 inches of mercury; and placing said container with thevacuum gauge thereon and showing approximately 2-3 inches of mercury ina refrigerator to permit the vacuum gauge to show approximately 5-9inches of mercury.